Method of making a joint



June 18, 1940. F. E. GRAY METHOD OF MAKING A JOINT Filed June 26, 1937 F515. 39 FEB. 39 /s3 40 33 INVENTOR fir j fi Patented June 18, 1940 PATENT OFFICE METHOD OF MAKING A JOINT Floyd E. Gray, Dayton, Ohio, assignor to Andrew A. Kucher, Dayton, Ohio Application June 26, 1937, Serial No. 150,595

14 Claims.

The present invention relates to the art of mechanically joining two pieces of material and more particularly to mechanically joining metals.

One of the objects of the present invention is to join two pieces of material by forming a slot in one of the pieces and then inserting the other piece into the slot. The piece which is inserted into the slot is provided with a shoulder along the side thereof. Pressure is then applied on the shoulder to force the inserted part sidewise into sealing engagement with the walls of the slot.

Another object of the invention is to join sheet metal with another material for example a cast-.

ing or forging by forming a slot in the material to receive the sheet metal. The sheet metal is overturned so that the edge thereof forms a shoulder at the side of the sheet. Pressure is applied to the edge to force the inserted part sidewise into sealing engagement with the walls of the slot. 1

Other and further objects and advantages will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred form of embodiment of the present invention is clearly shown.

' In the drawing:

Fig. 1 is a cross sectional view of a field frame and end bells of a unitary motor-compressor unit in which the end bells have been joined with the frame by my improved method;

Fig. 2 is a fragmentary sectional View of the field frame showing one manner of cutting the circular slot in the field frame;

Fig. 3 is a view similar to Fig. 2 but showing how a notch is cut in the bottom of the slot;

Fig. 4 is a fragmentary sectional view of the field frame, the end bell which is about to be inserted into the slot, and the tool to be used for applying pressure on the overturned edge of the end bell; and

Fig. 5 is a fragmentary sectional view showing the end bell joined with the field frame.

The present invention is applicable to different devices and for illustrative purposes, the embodiment illustrated is one in which the invention has many advantages. The drawing illustrates a motor-compressor unit including a motor frame 2|, usually formed of cast iron and provided with fins 22. The frame 2i carries a laminated field 24 suitably held in such position that the heat therefrom is readily conducted to the frame 2| whereby the heat can be dissipated through the fins 22. The frame includes a spider E 25 forming a bearing 26 for the motor shaft 28 and also supports th pump 29 by screws 30. End bells 32 for the unit 20 are attached to the frame 2l-by practicing my invention and when attached form a closed chamber 24.

Referring to the details of the present inven- I tion, a circular slot 33 is cut in the ends of the cylindrical frame 2|. The bottom of each slot is provided with an irregular or notched portion 34 preferably on the inner circular side of the slot for the reason hereinafter set forth. A 10 shoulder 35 is formed on the outer side of the bells 32 and in the preferred embodiment portion 36 of the material forming the bell. The bells are formed of sheet metal such as aluminum and in the specific illustration the metal is .062 inch 15 in thickness and of course the lip 31 formed by the bottom of the bell and the portion 36, will have a thickness of .124.

The slot 33 is .125 inch wide and therefore the lip 31 fits snugly within the slot. The bottomof $0 each slot at the notched portion is approximately .031 inch wider than the upper part of the slot. The slot 33 is formed as shown in Fig. 2 by a cutting tool 39 having a projection 40. After the slot is cut to the desired depth, it is moved in- 25 wardly to cut the notch 34 as shown in Fig. 3.

In securing the end bell in position, the lip 31 is placed in the slot 33 or in alignment therewith. In either case a ring 42 engages the shoulder 35 and first forces the rim 43 of the lip 31 80 to the bottom of the slot 33 and then on moving farther, forces the lip into the notch 34 as shown in Fig. 5. In the present embodiment the ring is moved downwardly so that the overturned edge will be depressed .125 inch after the edge 43 en 35 gages the bottom of the groove 33. That is, the lip is partly unfurled and pressed into the notch 34. When a lip 31 is unfurled in this manner, it will be sidewise or inwardly forced into the slot 33 and notch 34, and, in so doing, it must 40 necessarily distort to conform to the shape of the slot and notch and since the thickness of the lip 31 is substantially equal to the width of the slot 33, the material of the lip 31 must be crowded into the bottom of the slot in- 45 cluding the smaller radius notch. In other words the material will be forced against the side walls of the slot and the radius of the rim 43 must be decreased to occupy the space of the notch.- Therefore the material must be crowded and since the material is ductile, it will be dis-, persed into the porous walls of the casting and thereby thoroughly seal with the casting.

From the foregoing it will be seen that I have provided a relatively simple, speedy and efficient 66 method of joining two pieces of material. It is necessary only to force one of the pieces into the other and due to the fact that one of the pieces will be distorted in this operation, a hermetic joint is thereby provided.

It is also apparent that the physical strength of the joint does not depend entirely upon the crowding and the binding relationship of the metals but, the turned-in flange effect of the lip 31, as clearly shown in Fig. 5, also assists in retaining the joint.

The present invention is particularly applicable to joints between materials that cannot be readily welded such as sheet metal and cast iron. As

herein set forth the present invention is useful I in applying end bells to a motor compressor unit wherein it is desirable to hermetically seal the motor and compressor within a casing, as for example, to provide a unit such as that employed in refrigerating apparatus. Such unit becomes relatively warm while operating and it is desirable to dissipate this heat as by means of fins. Such fins should be in intimate heat exchange relation with the unit. The preferred construction is to form the fins integrally and this can be done by the present invention because the fins 22 can be cast integrally with the motor frame. By reason of this invention I have provided for sealing of a casing in which the mainpart thereof is formed of cast iron.

One of the distinct advantages of the present invention is that a large portion of the material of the end bell which forms the seal is not subjected to destructive stresses during the joining operation with the casting. The stresses during the joining operation are confined substantially entirely to the overturned portion 36 of the material, it of course being understood that the wall of the bell alongside the portion 36 will be worked to some extent due to crowding thereof during the joining operation, however, such working does not impair the mechanical strength of the metal.

Furthermore, the material of the end bell which is subjected to high pressures within the chamber 24, is not worked during the joining operation. By providing the shoulder 35 on the side of the bell proper, no abrupt bend is necessary on the bell proper and therefore the hell can be formed spherical and thereby withstand higher pressures.

If desirable both end bells 32 can be joined with the frame 2| simultaneously and in that case a second ring 42 would be provided. Preferably a hydraulic press is employed for actuating the ring or rings 42.

Although the present invention has been described in detail in regard to connecting sheet metal with .cast iron, it .is readily apparent that the same savings in cost of manufacture are accomplished when other materials, or like materials are joined.

While the form of embodiment of the present invention as herein disclosed constitutes a preferred form; it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

I claim:

1. The process of joining two pieces of material which consists in forming a slot in one of the pieces, forming a shoulder on the side of the other piece, and causing a part of the said other piece to be inserted into the mouth of the slot, and forcing the inserted material sidewise against one side wall of the slot by applying pressure,

onto the shoulder and through the mouth of the slot, to the material within the slot.

2. The process of joining two pieces of material which consists in forming a slot in one of the pieces, forming a shoulder on the side of the other piece, and causing a part of the said other piece including the shoulder to be inserted into the mouth of the slot, and forcing the inserted material sidewise against one side wall of the slot by applying pressure, onto the shoulder and through the mouth of the slot, to the material within the slot.

3. The process of joining two pieces of material which consists in forming in one of the pieces, a slot having an irregular side wall, forming a shoulder on the side of the other piece. and causing a part of the said other piece to be inserted into the mouth of the slot and causing pressure to be applied, on the shoulder and through the mouth of the slot, to the material within the slot to force a portion of the inserted part into the irregular portion of the side wall.

4. The process of joining two pieces of material which consists in forming a slot having an irregular side wall in one of the pieces, forming a shoulder on the side of the other piece, and causing a part of the said other piece to be inserted into the slot with the shoulder disposed adjacent the side of the slot opposite the irregular side wall and causing pressure to be applied, on the shoulder and through the mouth of the slot, to the material within the slot to force a portion of the inserted part into the irregular portion of the side wall.

5. The process of joining a piece of material with a sheet of metal which consists in forming a slot in the piece, overturning the edge of the sheet metal to increase the thickness thereof to substantially equal the width of the slot and to form a shoulder at the side of the sheet metal, and causing the overturned part of the metal to be inserted into the slot and causing pressure to be applied on the shoulder to cause at least partial unfurling of the overturned edge and to force the inserted part sidewise.

6. The process of joining a piece of material with a sheet of metal which consists in forming a slot having an irregular side wall in the piece, overturning the edge of the sheet metal to increase the thickness thereof to substantially equal the width of the slot and to form a shoulder at the side of the sheet metal, and causing the overturned part of the metal to be inserted into the slot and causing pressure to be applied on the shoulder to cause at least partial unfurling of the overturned edge and to force the inserted part into the irregular portion of the side wall.

7. The process of joining two pieces of material which consists in forming in one of the pieces a slot having opposed stationary side walls and a bottom, forming a shoulder on the side of the other piece,'and causing a part of the other piece to be inserted into the mouth ofthe slot, causing the lower part of the inserted material to flow to conform to the contour of the lower part of the slot without distorting the slot by applying pressure by a tool directly on the shoulder, and then removing the tool.

8. The process of joining two pieces of material which consists in forming a shoulder on the side of one of the pieces, inserting the said piece into a slot of which the other piece forms at least one side wall of the slot, causing the material of the inserted piece to be forced sidewise against the said' one wall of the slot by applying pressure on the shoulder and through the mouth of the slot and limiting otherwise spreading of the material of the first piece by other of the walls of the slot.

9. The process of joining two pieces of mate rial which consists in forming a shoulder on the side of one of the pieces, inserting the said piece into a slot of which the other piece forms at least one side wall of the slot and which wall includes an irregular portion, causing the material of the inserted piece to be forced sidewise to flow to the shape of the irregular portion by applying pressure on the shoulder and through the mouth of the slot and limiting otherwise spreading of the material by. other of the walls of the slot.

10. The process of joining two pieces of material which consists in forming a shoulder on the side of one of the pieces, causing the said piece to be forced sidewise against a wall of the other piece of material by applying pressure by a tool directly on the shoulder while the material to be forced sidewise is closely confined by stationary walls of a slot of which said wall of the said other piece is one of the side walls of the slot, and then removing the'tool.

11. The process of Joining two pieces of material which consists in forming a shoulder on the side of one of the pieces, causing the said piece to flow into an irregularly shaped wall of the other piece by applying pressure by a tool directly on the shoulder while the material which is to flow is closely confined by stationary walls 35 of a slot or which said irregularly shaped wall is one of the said walls of the slot, and then remoying the tool.

12. The process of joining two non-linear pieces of material which consists in forming a shoulder on the longer side of one of the pieces; causing said piece to be forced against a wall of the other piece, which is shorter in length than the length of the first piece, by applying pressure on the shoulder while the material of the first piece, being forced against said wall, is closely confined in a slot of which the said wall is one of the side walls of the slot.

13. The process of joining two pieces of material which consists in forming, on one of said pieces, an endless lip, having a shoulder on the outside wall thereof; causing said lip to be forced about a. wall of the other pieces, having a shorter perimeter than the inner perimeter of the lip, by applying pressure on the shoulder while the material of the lip is closely confined in an endless slot of which the said wall is the inside wall of the slot.

14. The process of joining two pieces of material which consists in forming in one of the pieces an endless narrow and deep slot, the inside wall of which having a shorter perimeter below the mouth than the top perimeter, forming an endless lip on the other pieces conforming to register with the mouth of the slot, forming a shoulder on the outer perimeter of the lip, inserting the lip in the slot,. and causing the lip to closely embrace the shorter perimeter of the inside wall of the slot by applying pressure on the shoulder the slot.

while the lip is confined in FLOYD E. GRAY. 

